Ruby implementation of the command line view function source code _ruby special Topics

If you want to see the source code for the ActiveRecord update_attribute function, a more common approach is to search for Def Update_attribute directly from the Rails source. Blog The Pragmatic Studio introduces a more convenient technique to enable direct access to the editor in the Ruby command line.

The object of the Update_attribute method can be obtained by the Object#method method, while Method#source_location returns the file and location of the method definition. With this information, you can start the editor to view the source code:

Copy Code code as follows:

> method = User.first.method (: update_attribute)
User Load (0.5ms) SELECT ' users '. * from ' users ' LIMIT 1
=> #<method:user (ActiveRecord::P ersistence) #update_attribute >

> location = method.source_location
=> ["/users/wyx/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.2.11/lib/active_record/persistence.rb",
177]

> ' Subl #{location[0]}:#{location[1]} '
=> ""

Encapsulate this code as a function, add it to the. Pryrc or. IRBRC:

Copy Code code as follows:

Def source_for (object, method)
Location = Object.Method (method). source_location
' Subl #{location[0]}:#{location[1]} ' if location && location[0]!= ' (eval) '
Location
End

If you want to view the instance method Update_attribute for User, you can call it directly in PRY/IRB

Copy Code code as follows:

Source_for (User.first,: Update_attribute)

If you want to use another editor, replace the Subl #{location[0]}:#{location[1]} with the corresponding command line for this editor:

Copy Code code as follows:

# TextMate
Mate #{location[0]}-l #{location[1]}

# Macvim
Mvim #{location[0]} +#{location[1]}

# Emacs
Emacs {Location[0]} +#{location[1]}